False-twist arrangement

ABSTRACT

For the production of synthetic, texturised fine yarns or filaments, a false-twist arrangement is used which comprises a rotary tube provided on the entry side with an annular bead having a rounded, highly polished edge, thread guides being so arranged that the filament contacts the rotary tube only at the highly polished edge of the bead and encloses between the supply and discharge direction an angle greater than 90*.

United States Patent 11 1 1111 3,756,006 Heinroth et al. 1 Sept. 4, 1973 I FALSE-TWIST ARRANGEMENT 3,668,855 6/1972 LeCSOII et al. 57 774 3,668,856 6 1972 R' ht 57 77.4 I751 Karl'August einmh; Herbert 3,564,833 2i1971 11 6 1118 57/774 Neumann; kudiPauschel'; 3,094,834 6/1963 Deeley et al 57/51.6 x Hans-D t r Ju s h a; Ha Ba 3,478,506 11 1969 Kawashhima 57 774 x all of Dormagen, Germany Asslgnee: Bayer Akuengesenschan Primary Examiner-Donald E. Watkins Leverkusen, Germany Attorney-Burgess, Dmklage & Sprung I22] Filed: Feb. 4, 1971 121] App]. No.2 112,643

[57] ABSTRACT [30] Foreign Application Priority Data Feb. 19, I970 Germany P 20 07 508.5 For the production of synthetic, texturised fine yarns or filaments, a false-twist arrangement is used which com- [52] US. Cl. 57/77.4 prises a rotary tube provided on the entry side with an [51] Int. Cl. D02g l/06, DOlh 7/92 annular bead having a rounded, highly polished edge, [58] Field of Search 57/773, 77.4, 77.45, thread guides being so arranged that the filament con- 57/5 1 .6 tacts the rotary tube only at the highly polished edge of the bead and encloses between the supply and dis- [56] References Cited charge direction an angle greater than 90.

UNITED STATES PATENTS 3,066,473 12/ 1962 Maeda 57/77.4 9 Claims, 2 Drawing Figures 10 l 2 2 l l 0 PATENTEflstr 4 ms SHEEI 2 0f 2 FALSE-TWIST ARRANGEMENT The present invention relates to a false-twist arrangement for the production of synthetic, texturised fine yarns or filaments, comprising a rotary tube which is provided on its entry side with an annular bead of which the opening diameter is smaller than the internal diameter of the rotary tube, and thread guides.

Various constructional forms of false-twist devices are already known. By way of example, German Specification No. 1,435,514, as open to inspection, shows a rotary tube which is formed with annular beads, the surfaces of which have a high coefficient of friction. A similar arrangement is described in German Auslegeschrift No. 1,205,652. In this case, the rotary tube is lined with a bushing which has ends which widen out, the bushing having a smooth, convex, internal surface and being of a material with a high coefficient of friction. The entry and exit angles of the filament are between 45 and 90. Rubber is used as the material for the annular beads or bushing. It is understandable that the frictional coefficient may change since this material is subjected to heavy wear. The uniformity of the texturising twist is then no longer guaranteed. In addition, the rubber dust can adhere to the treated filament and soil the latter.

Finally, a false-twist arrangement is also known from German Patent Specification No. 185,580, in which the filament is drawn off by means of a ring-type winding means as a balloon from the feed rolls. The false-twist arrangement is disposed between the feed rolls and the ring-winding means so that the filament thrown out in the manner of a balloon bears on the entry and exit beads of the false-twist arrangement. The entry bead consists of ribbed cast iron, in order to increase the friction and the exit portion consists of steel. Apart from the fact that it is difficult to manufacture the rotary tube, since it consists of several parts, this arrangement can only be used for the manufacture of weakly texturised filaments, because there is only a low filament tension. The ribbing on the entry bead applies a very strong load to the filament and can damage it.

Accordingly, the object of this invention is to produce texturised fine yarns or filaments with at least 1,500 false twists per metre, without any fluctuations in the texturising or damage to the filament, by using a device which is of a simple construction and which is independent of wear as regards its action.

This object is achieved according to the invention by using an arrangement comprising an annular bead with a rounded, highly polished edge, thread guides being so arranged that the filament or tow of filaments contacts the rotary tube only at the highly polished edge and encloses between the entry and exit directions an angle a of more than 90.

The effect hereby achieved is that, even with wear on the edge of the annular bead of the rotary tube, the texturising of the filament is not subject to any fluctuations, since the highly polished edge of the bead guarantees a constant twisting action, because the sliding friction of the filament can scarcely change the surface of the edge. The use as known per se of thread guides ensures a constant thread tension during the passage thereof through the false-twist arrangement. The texturising speed can be kept very high. The false-twist arrangement according to the invention is suitable for the texturising of filaments or tows of filaments consisting of fully synthetic high polymers, more especially polyamides, of high molecular weight, linear polyesters and of acrylonitrile polymers.

One particular constructional embodiment of the false-twist arrangement according to the invention, in particular for the production of multi-filament crimped yarns, is characterised in that the exit side of the rotary tube is also provided with an annular bead, which has a rounded, highly polished edge, and the filament or tow of filaments is guided diagonally through the rotary tube, and also bears against the annular bead on the exit side of the rotary tube.

Due to the direction of rotation of the entry annular bead, a false-twist into the fixing zone in the S-direction is produced. By the contact of the tow of filaments with the exit annular bead, the tow of filaments experiences a rotation in the Z-direction. The particular feature of this arrangement consists in that, on the path between the annular beads at the entry and exit ends, false twists of opposite direction in the tow of filaments run opposite to one another. This is caused by the different thread tensions on the rotary tube between the entry and exit sides, these tensions being dictated by the stretch texturising. On account of the different frictional conditions connected therewith on the entry and exit annular beads, there is obtained in the intermediate zone a periodic accumulation and release of the false twists in the S-direction and Z-direction. The resultant intensive intermingling and crimping of the individual capillaries of the tow of filaments leads to a highly texturised, bulk yarn, which is rotated throughout its length alternately in the S-direction and 2- direction.

In a manner simple as regards construction, the rotary tube can be made as a one-part, turned element. According to one particular constructional embodiment, the annular head on the exit side is, however, formed as a member which can be fitted and which can, for example, be connected by a screw-threaded connection to the rotary tube which is provided on the entry side with an annular bead. In this way, the actual rotary tube can be used for different texturising processes.

Advantageously a metal and in particular steel is to be considered as suitable for the rotary tube and for the annular beads, but chemical materials based on polyurethane which have a high resistance to wear can also be considered.

The false-twist arrangement according to the invention is illustrated in strictly diagrammatic form and in longitudinal section by means of the two constructional embodiments exemplified in the drawings and the arrangement is to be hereinafter explained. In the draw- FIG. 11 shows an arrangement having an annular bead on the entry side of the rotary tube; and

FIG. 2 shows an arrangement with an additional annular head on the exit side of the rotary tube.

In FIG. 1, the false-twist arrangement consists of a bearing member 1 in which are supported ball-bearings 2 on which is mounted a steel rotary tube 3. The rotary tube projects on one side far beyond the bearing member l and is provided with an annular keyway 4, through which runs a driving belt 5. Formed on the end of the projecting rotary tube 3 is an annular bead 6 with a highly polished edge 7, against which bears the filament 8 which is to be texturised. The opening diameter 11,, of the annular bead 6 is smaller than the internal diameter d,, of the rotary tube 3, so that the filament 8 leaves the rotary tube 3 without touching the latter. The end face of the rotary tube 3 is set back from the highly polished edge 7 in an outward direction, so that the filament 8 only bears on the edge 7. By the particular arrangement or setting of a thread guide 10 disposed on the entry side, the entering thread or filament 8 forms an angle of 10 with the perpendicular to the axis of rotation of the tube 3. The exit angle of the thread 8, measured between the thread 8 and an axis parallel to the edge 7, is 20, corresponding to the setting of a thread guide 11 arranged on the exit side. Therefore, between the entry direction and exit direction, the thread 8 encloses an angle a of 100.

The same reference numerals are used in FIG. 2, since the constructional example of the arrangement only differs from that according to FIG. 1 by an additional annular bead on the exit side of the rotary tube and by a different method of guiding the thread.

Supported in the bearing member 1 are the ballbearings 2, on which rotates the steel rotary tube 3. It is driven by the belt extending around the key-way 4. The annular bead 6 on the entry side has a highly polished edge 7, against which the thread 8 bears. The end face 9 is set back towards the rim. The thread guide on the entry side is so arranged that the entering thread or filament 8 encloses an angle of 10 with the perpendicular to the axis of rotation of the rotary tube 3. On the exit side of the rotary tube 3, there is arranged a second steel annular bead 12, which is constructed as a fitting and is connected by a screw-threaded connection 13 to the rotary tube 3. It also has a highly polished edge 14. The opening diameters d and d, of the annular beads 6 and 12 on the entry and exit sides correspond to each other and are smaller than the internal diameter d of the rotary tube 3. The discharge angle of the thread 8 from the edge 7 corresponds to the supply angle for the edge 14, because the thread 8 is guided diagonally through the rotary tube 3. In this constructional example, the angle a, which is enclosed by the thread 8 guided around the edge 7, is 100. Because of the symmetrical conditions, the thread 8 encloses an angle a which is also 100 with the deflection around the edge 14, due to suitable setting of the thread guide 10 on the exit side. The discharge angle of the thread 8 from the edge 14 is accordingly also 10, like the supply angle to the edge 7. On the edge 7, the thread or bundle of threads 8 is rotated in the S- direction, and on the edge 14 in the Z-direction.

Example 1 A polyamide monofilament (polyamide 6 dtex 20/1) is stretched in the ratio 1:35 in a drafting mechanism and is guided at a temperature of 170C. through a heated zone into the false-twist arrangement according to the invention, as shown in FIG. 1 with a filament speed of 500 m/min. The rotary tube is rotating at Example 2 A polyester multi-filament (dtex 22/3) is stretched by means of a drafting mechanism in the ratio 1:40 and is guided at a temperature of 200 C. through a heated zone into the false-twist arrangement according to the invention as shown in FIG. 1, with a filament speed of 400 mlmin. The tube is rotating at 14,000 r.p.m. The radius of the highly polished edge of the annular bead is 3.0 mm and the opening diameter of this bead is 30 mm. The angle enclosed by the filament deflected on the edge is and the entry angle, measured in relation to the perpendicular to the axis of rotation of the rotary tube, is 15. The texturised filament shows a curl value of 260 twists per metre.

Example 3 A polyamide multi-filament (polyamide 6.6, dtex 33/6) is stretched in a drafting mechanism in the ratio 1:3.6 and is guided at a temperature of 170 C. through a heated zone into the false-twist arrangement according to the invention in accordance with the constructional example shown in FIG. 2, with a filament speed of 550 mlmin. The speed of rotation of the rotary tube is 14,500 r.p.m. The highly polished edges of the annular heads have a radius of 4.0 mm. The opening diameter of the annular beads is 28 mm. The filament travels at an angle of 10 to the perpendicular to the axis of rotation of the rotary tube into the arrangement and leaves the latter at the same angle. The angles enclosed by the filament at the entry edge and the exit edge are in each case. The curl value of this material is on average 480 twists per metre. The material has a coldwater shrinkage of 55-66 percent.

We claim:

1. Apparatus suitable for false twisting of synthetic elements such as yarns or filaments comprising:

a. a hollow rotatably mounted tube having an inlet end for receiving the element and an outlet end for exiting of the element, and an inwardly extending annular bead at the inlet end providing an inlet edge having a diameter smaller than the internal diameter of the tube, said inlet edge being rounded and highly polished,

. an inlet roller and an outlet roller disposed, respectively, adjacent the inlet end and outlet end of the tube, for guiding the element first over the edge of the annular bead in contact therewith so that at the inlet end the element contacts only said edge, through the tube and out the outlet end thereof, and so that the element on either side of the inlet edge defines an angle a of more than 90.

2. Apparatus according to claim 1, the hollow tube having an inlet end face extending radially outwardly from the annular bead and set back from the annular bead in the direction of travel of the element through the tube.

3. Apparatus according to claim 2, the inlet roller being positioned so that the element moves therefrom to the annular bead, radially inwardly and rearwardly.

4. Apparatus suitable for false twisting of synthetic elements such as yarns or filaments comprising:

a. a hollow rotatably mounted tube having an inlet end for receiving the element and an outlet end for exiting of the element, and an inwardly extending annular bead at the inlet end and at the outlet end providing an inlet edge and an outlet edge having a diameter smaller than the internal diameter of the tube, said inlet edge and outlet edge being rounded and highly polished,

. an inlet roller and an outlet roller disposed, respectively, adjacent the inlet end and outlet end of the tube, for guiding the element first over the edge of the annular bead at the inlet end in contact therewith so that at the inlet end the element contacts only said edge, through the tube and out the outlet end thereof, over the edge of the annular bead at the outlet end in contact therewith so that at the outlet end the element contacts only said edge, and so that the element on either side of the inlet edge defines an angle a of more than 90.

5. Apparatus according to claim 4, the hollow tube having an inlet end face and an outlet face extending radially outwardly from, respectively, the inlet annular bead and the outlet annular bead, the end faces being set back from the annular beads towards the body of the hollow cylinder.

6. Apparatus according to claim 5, the inlet roller being positioned so that the element moves therefrom to the annular bead, radially inwardly and rearwardly, the outlet roller being positioned so that the element moves from the outlet annular bead to the outlet roller, radially outwardly and rearwardly.

7. Apparatus according to claim 4, the hollow cylinder comprising a body portion and an outlet end member detachably mounted on the body portion, said outlet end member comprising said outlet annular bead.

8. Apparatus according to claim 5, the hollow cylinder comprising a body portion and an outlet end member detachably mounted on the body portion, said outlet end member comprising said outlet annular bead.

9. Apparatus according to claim 6, the hollow cylinder comprising a body portion and an outlet end member detachably mounted on the body portion, said outlet end member comprising said outlet annular bead. 

1. Apparatus suitable for false twisting of synthetic elements such as yarns or filaments comprising: a. a hollow rotatably mounted tube having an inlet end for receiving the element and an outlet end for exiting of the element, and an inwardly extending annular bead at the inlet end providing an inlet edge having a diameter smaller than the internal diameter of the tube, said inlet edge being rounded and highly polished, b. an inlet roller and an outlet roller disposed, respectively, adjacent the inlet end and outlet end of the tube, for guiding the element first over the edge of the annular bead in contact therewith so that at the inlet end the element contacts only said edge, through the tube and out the outlet end thereof, and so that the element on either side of the inlet edge defines an angle Alpha of more than 90*.
 2. Apparatus according to claim 1, the hollow tube having an inlet end face extending radially outwardly from the annular bead and set back from the annular bead in the direction of travel of the element through the tube.
 3. Apparatus according to claim 2, the inlet roller being positioned so that the element moves therefrom to the annular bead, radially inwardly and rearwardly.
 4. Apparatus suitable for false twisting of synthetic elements such as yarns or filaments comprising: a. a hollow rotatably mounted tube having an inlet end for receiving the element and an outlet end for exiting of the element, and an inwardly extending annular bead at the inlet end and at the outlet end providing an inlet edge and an outlet edge having a diameter smaller than the internal diameter of the tube, said inlet edge and outlet edge being rounded and highly polished, b. an inlet roller and an outlet roller disposed, respectively, adjacent the inlet end and outlet end of the tube, for guiding the element first over the edge of the annular bead at the inlet end in contact therewith so that at the inlet end the element contacts only said edge, through the tube and out the outlet end thereof, over the edge of the annular bead at the outlet end in contact therewith so that at the outlet end the element contacts only said edge, and so that the element on either side of the inlet edge defines an angle Alpha of more than 90*.
 5. Apparatus according to claim 4, tHe hollow tube having an inlet end face and an outlet face extending radially outwardly from, respectively, the inlet annular bead and the outlet annular bead, the end faces being set back from the annular beads towards the body of the hollow cylinder.
 6. Apparatus according to claim 5, the inlet roller being positioned so that the element moves therefrom to the annular bead, radially inwardly and rearwardly, the outlet roller being positioned so that the element moves from the outlet annular bead to the outlet roller, radially outwardly and rearwardly.
 7. Apparatus according to claim 4, the hollow cylinder comprising a body portion and an outlet end member detachably mounted on the body portion, said outlet end member comprising said outlet annular bead.
 8. Apparatus according to claim 5, the hollow cylinder comprising a body portion and an outlet end member detachably mounted on the body portion, said outlet end member comprising said outlet annular bead.
 9. Apparatus according to claim 6, the hollow cylinder comprising a body portion and an outlet end member detachably mounted on the body portion, said outlet end member comprising said outlet annular bead. 